About Optics & Photonics TopicsOSA Publishing developed the Optics and Photonics Topics to help organize its diverse content more accurately by topic area. This topic browser contains over 2400 terms and is organized in a three-level hierarchy. Read more.

Topics can be refined further in the search results. The Topic facet will reveal the high-level topics associated with the articles returned in the search results.

Abstract

We theoretically study the pulse-contrast degradation of optical parametric chirped pulse amplification (OPCPA) system pumped by a temporally phase-modulated laser. We reveal two physical mechanisms that reduce the contrast in such a parametric process: the effect of phase transfer caused by group-velocity mismatch (GVM) and the effect of FM-to-AM conversion caused by group-velocity dispersion (GVD). Degradation of the contrast is quantified via numerical simulations. To reduce the effect of phase transfer, a pair of OPCPAs seeded by the signal and idler respectively, is studied for effectively improving the contrast in such a case with pump phase modulation. The results presented in this paper are of particular importance for extremely intense laser applications requiring high contrast.

Amplified chirped signal pulse and its phase modulation (inset) in both time (a) and frequency (b) domains under the conditions with GVMi-p and small-signal amplification. For comparison, output pump pulse and its phase are also given (c). Parameters in the simulations, LNL = 0.17L, L = 10mm, Es(0) = 10−6, gain~6.4 × 107, Lip = 0.5L (red curve) and Lip = L (black curve). Other parameters are the same as in Fig. 1.

Phase modulation in time domain (a), spectrum and its phase modulation (b) of output amplified chirped signal pulse under the conditions with GVMi-p and small-signal amplification, from the first stage (black curve), from the second stage with signal seeding (red curve), and with idler seeding (blue curve). Parameters in the simulations, LNL = 0.25L, L = 10mm, Es(0) = 10−6, gain~2 × 1010, Lip = L. Other parameters are the same as in Fig. 1.

Intensities of the recompressed signal pulse under the conditions with GVMi-p and small-signal amplification, from the first stage (a), from the second stage with signal seeding (b), and with idler seeding (c). Other parameters are the same as in Fig. 11.